Electric heater and drier.



G.- N. BLANCHARD.

ELECTRIC HEATER AND DRIER.

APPLICATION FILED FEB. 21, 1908.

901,871. I Patented Oct. 20, 1908.

WITNESSES INYENTOR 376 N BZana/Zard 74%)) ATTORNEY GEORGE N. BLANOHARD,OF saur zaacisco, ELECTRIC MANUFACTURING 00.,

OALIFORNIA, ASSIGNOR OF ONE-HALF TO THE OF SAN FRANCISCO, CALIFORNIA.

ELECTRIC EATE ANDDRIER.

No. eoi,e71.

Specification of Letters Patent.

Patented Oct. 20, 1908.

"a iicatibn'meareb 21, 1908. Serial m. 417,077.

To all whom it may concern:

Be it'known that I, GE0RGE N. BLANCHARD, citizen of the UnitedStates,.residing in the city and county of San Francisco and State ofCalifornia, have invented new and useful Improvements in ElectricHeaters and Driers, of which the following is a specification.

My invention relates to an apparatus for producing currents of hot airfor therapeutic and various other or similar uses where hot air isrequired.

It consists in the novel construction and disposition of the electricalresistance coil through which air is driven for the purpose of heatingthe same, and in details of construction which will bemore fullyexplained by reference to the accompanying drawings, in which Figure 1is a side elevation, partfyin sec-, tion, of the device. Fig. 2 is aperspective view of the resistance coil. Fig. 3 is an end view of tubeand coil. Fig. 4 is a transverse f section of a coil.

Various devices have been em loyed forv heating a current of air to besu sequently used 5 such devices usually including electricallyresistant wires of small diameter so disposed that currents of air may.-be passed over these wires, which being heated by the electrical currentwill impart the heat to the vair which is passing. 4

D'fiiculty is experienced in maintaining an equabletemperature of theheating wires, and at the same time utilizing to the fullest extenttheir heating ability.

Within a suitable case, C, the fan, A, is adapted to operatethroughpower communicated thereto from any well known type of electricmotor, B, shown by dotted lines in Fig. 1 said fan case having adischarge pipe or passage through which the blast of air is driven. Thispassage may be round or rectangular as shown,

The heating coil consists ,of'fine wires 3 which are wound upon apyramidal shaped supporting frame having a base adapted'to fit therectangular passage 2. This base may be constructed of any suitablematerial, and i ductor, such as lava. The wires 3 are wound over theedges. of these plates which are notched or toothed sothat each windingof wire will be kept separate from the next adjacent one, and eachwinding will form a ing from the smaller to the larger end. When thuswound, the ends of theseresistant wires are respectively connected withconducting wires 5, through which a current "In my be passed, and thecurrent being in excess of the capacity of the wires 2, the wire will beheated to as high a temperature as may be desired. This resistance coilbeing completed, is then inserted into the rectangular tube 2, the edgesof' the cross plates at their largest dimension fitting into the anglesof the tube, and the resistance wires 2 which are wound upon the largestportion ofthis frame are substantially close to the opposite end, thewires ofthis coil arenear to the center.

It has been found that Where coils of wire are disposed longitudinallywithin an airconveying tube, and these coils of substantially the samediameter, .the air striking and the coil at this end will becorrespondingly cooled. As the heated air passes on through the coil,its temperature rises, and near the discharge end it becomes so high,that the coil itself will be unduly heated at this end; thus the coilwill have a comparatively low temperature Where the air first strikesit, and a high temperature where the air is leaving it.

I If the wires are simply disposed transversely of the passage in asingle' plane, it would not be possible to insert a sufficient length ofresistance wire choking the air passage.

By my invention the whole surface of the resistance wire is uniformlysubjected to the cold blast of air from the propelling fan, at

shape of the resisting unit, a suflicient length of resistance wire canbensed, with ample space between the turns of said resistance. wire toadmit of free passage of air.

The rectangular or pyramidal form of the from the conducting tube. v

The fan case may be provided with a suitthe first coil will commence tobe heated,

, without unduly the same time on. account of the pyramidal coil,renders it easy to insert and remove rectangle; theserectanglesgradually enlarg- '1' inner periphery of the tube, while at the ablehandle D whereby the device may be freely moved about so as to dry theparts to be subjected to the current of air.

Having thus described my invention, what I claim and desire to secure byLetters Patent is 1. In an air-heating apparatus, an airforcingmechanism, a discharge tube, and a pyramidal electrical resistance coilfixed within said tube.

2. In an apparatus of the character described, anair discharge passage,a resistance coil, consisting of wires wound upon a divergent orpyramidal insulated frame, and located in said passage.

3. In an apparatus of the character described, an air discharge passa e,a frame having insulated edges adapted coiled thereon, and graduallydivergent from one end to the,other,'said frame being fitted in the airdischarge assage, and electrical currentconnections with the resistantcoil.

In testimony whereof I have hereunto set .my hand in presence oftwosubscribing witto receive naked electrically resistant wires which are a

